scholarly journals Climate Variability and the U.S. Corn Belt: ENSO and AO Episode-Dependent Hydroclimatic Feedbacks to Corn Production at Regional and Local Scales*

2015 ◽  
Vol 19 (6) ◽  
pp. 1-32 ◽  
Author(s):  
Olivia Kellner ◽  
Dev Niyogi
Keyword(s):  
El Niño ◽  
El Nino ◽  
Growing Season ◽  
Yield Potential ◽  
Corn Belt ◽  
Corn Yield ◽  
Corn Production ◽  
Enso Events ◽  
Temperature And Precipitation ◽  
The U.S

Abstract El Niño–Southern Oscillation (ENSO) and Arctic Oscillation (AO) climatology (1980–2010) is developed and analyzed across the U.S. Corn Belt using state climate division weather and historic corn yield data using analysis of variance (ANOVA) and correlation analysis. Findings provide insight to agroclimatic conditions under different ENSO and AO episodes and are analyzed with a perspective for potential impacts to agricultural production and planning, with findings being developed into a web-based tool for the U.S. Corn Belt. This study is unique in that it utilizes the oceanic Niño index and explores two teleconnection patterns that influence weather across different spatiotemporal scales. It is found that the AO has a more frequent weak to moderate correlation to historic yields than ENSO when correlated by average subgrowing season index values. Yield anomaly and ENSO and AO episode analysis affirms the overall positive impact of El Niño events on yields compared to La Niña events, with neutral ENSO events in between as found in previous studies. Yields when binned by the AO episode present more uncertainty. While significant temperature and precipitation impacts from ENSO and AO are felt outside of the primary growing season, correlation between threshold variables of episode-specific temperature and precipitation and historic yields suggests that relationships between ENSO and AO and yield are present during specific months of the growing season, particularly August. Overall, spatial climatic variability resulting from ENSO and AO episodes contributes to yield potential at regional to subregional scales, making generalization of impacts difficult and highlighting a continued need for finescale resolution analysis of ENSO and AO signal impacts on corn production.

scholarly journals The Response of Tropical Atmospheric Energy Budgets to ENSO*

2013 ◽  
Vol 26 (13) ◽  
pp. 4710-4724 ◽  
Author(s):  
Michael Mayer ◽  
Kevin E. Trenberth ◽  
Leopold Haimberger ◽  
John T. Fasullo
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Warm Pool ◽  
Smooth Transition ◽  
Energy Budgets ◽  
Enso Events ◽  
El Niño Modoki ◽  
Static Energy ◽  
The Tropics

Abstract The variability of zonally resolved tropical energy budgets in association with El Niño–Southern Oscillation (ENSO) is investigated. The most recent global atmospheric reanalyses from 1979 to 2011 are employed with removal of apparent discontinuities to obtain best possible temporal homogeneity. The growing length of record allows a more robust analysis of characteristic patterns of variability with cross-correlation, composite, and EOF methods. A quadrupole anomaly pattern is found in the vertically integrated energy divergence associated with ENSO, with centers over the Indian Ocean, the Indo-Pacific warm pool, the eastern equatorial Pacific, and the Atlantic. The smooth transition, particularly of the main maxima of latent and dry static energy divergence, from the western to the eastern Pacific is found to require at least two EOFs to be adequately described. The canonical El Niño pattern (EOF-1) and a transition pattern (EOF-2; referred to as El Niño Modoki by some authors) form remarkably coherent ENSO-related anomaly structures of the tropical energy budget not only over the Pacific but throughout the tropics. As latent and dry static energy divergences show strong mutual cancellation, variability of total energy divergence is smaller and more tightly coupled to local sea surface temperature (SST) anomalies and is mainly related to the ocean heat discharge and recharge during ENSO peak phases. The complexity of the structures throughout the tropics and their evolution during ENSO events along with their interactions with the annual cycle have often not been adequately accounted for; in particular, the El Niño Modoki mode is but part of the overall evolutionary patterns.

scholarly journals Switch Between El Nino and La Nina is Caused by Subsurface Ocean Waves Likely Driven by Lunar Tidal Forcing

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jialin Lin ◽  
Taotao Qian
Keyword(s):  
El Niño ◽  
El Nino ◽  
Ocean Waves ◽  
La Niña ◽  
Slow Phase ◽  
Enso Events ◽  
The Past ◽  
La Nina ◽  
Subsurface Ocean ◽  
Sst Anomaly

Abstract The El Nino-Southern Oscillation (ENSO) is the dominant interannual variability of Earth’s climate system, and strongly modulates global temperature, precipitation, atmospheric circulation, tropical cyclones and other extreme events. However, forecasting ENSO is one of the most difficult problems in climate sciences affecting both interannual climate prediction and decadal prediction of near-term global climate change. The key question is what cause the switch between El Nino and La Nina. For the past 30 years, ENSO forecasts have been limited to short lead times after ENSO sea surface temperature (SST) anomaly has already developed, but unable to predict the switch between El Nino and La Nina. Here, we demonstrate that the switch between El Nino and La Nina is caused by a subsurface ocean wave propagating from western Pacific to central and eastern Pacific and then triggering development of SST anomaly. This is based on analysis of all ENSO events in the past 136 years using multiple long-term observational datasets. The wave’s slow phase speed and decoupling from atmosphere indicate that it is a forced wave. Further analysis of Earth’s angular momentum budget and NASA’s Apollo Landing Mirror Experiment suggests that the subsurface wave is likely driven by lunar tidal gravitational force.

scholarly journals ENSO flavors in a tree-ring δ<sup>18</sup>O record of <i>Tectona grandis</i> from Indonesia

2015 ◽  
Vol 11 (10) ◽  
pp. 1325-1333 ◽  
Author(s):  
K. Schollaen ◽  
C. Karamperidou ◽  
P. Krusic ◽  
E. Cook ◽  
G. Helle
Keyword(s):  
Tree Ring ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Central Pacific ◽  
Central Pacific El Niño ◽  
Enso Events ◽  
Proxy Records ◽  
El Niño Events ◽  
El Nino Events

Abstract. Indonesia's climate is dominated by the equatorial monsoon system, and has been linked to El Niño-Southern Oscillation (ENSO) events that often result in extensive droughts and floods over the Indonesian archipelago. In this study we investigate ENSO-related signals in a tree-ring δ18O record (1900–2007) of Javanese teak. Our results reveal a clear influence of Warm Pool (central Pacific) El Niño events on Javanese tree-ring δ18O, and no clear signal of Cold Tongue (eastern Pacific) El Niño events. These results are consistent with the distinct impacts of the two ENSO flavors on Javanese precipitation, and illustrate the importance of considering ENSO flavors when interpreting palaeoclimate proxy records in the tropics, as well as the potential of palaeoclimate proxy records from appropriately selected tropical regions for reconstructing past variability of. ENSO flavors.

Long term population changes of fur seals Arctocephalus gazella and Arctocephalus tropicalis on subantarctic (Crozet) and subtropical (St. Paul and Amsterdam) islands and their possible relationship to El Niño Southern Oscillation

1994 ◽  
Vol 6 (4) ◽  
pp. 473-478 ◽  
Author(s):  
C. Guinet ◽  
P. Jouventin ◽  
J-Y. Georges
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Enso Events ◽  
Fur Seals ◽  
Fur Seal ◽  
Arctocephalus Tropicalis

The population trend over the last decade for subantarctic fur seals (Arctocephalus tropicalis) on Amsterdam and St. Paul islands and on Possession Island (Crozet Archipelago) and Antarctic fur seals (A. gazella) on Possession Island are analysed. At Amsterdam Island, based on pup counts, the subantarctic fur seal population appears to have stabilized after a period of rapid growth. At Possession Island subantarctic fur seal and Antarctic fur seal, with respective annual growth rates of 19.2 and 17.4%, are reaching the maximum growth rate for the genus Arctocephalus. Annual pup censuses at Possession Island since 1978 indicate important variations from year to year with pup production for A. gazella significantly lower the year after an El Niño Southern Oscillation (ENSO) event, but with no such relationship for A. tropicalis. Several other long term demographic studies of seabirds and marine mammals at different breeding locations in the Southern Ocean indicate that the breeding success of several of these predators appears to be widely affected in years which appear to be related to the ENSO events. To clarify this, it is necessary to analyse in more detail the demographic data obtained for the different subantarctic and Antarctic locations where long term monitoring programmes are conducted.

scholarly journals Diagnosis of Anomalous Winter Temperatures over the Eastern United States during the 2002/03 El Niño

2006 ◽  
Vol 19 (21) ◽  
pp. 5624-5636 ◽  
Author(s):  
Lisa Goddard ◽  
Arun Kumar ◽  
Martin P. Hoerling ◽  
Anthony G. Barnston
Keyword(s):  
United States ◽  
El Niño ◽  
El Nino ◽  
Winter Season ◽  
Temperature Pattern ◽  
Eastern United States ◽  
Seasonal Forecasts ◽  
Temperature Anomalies ◽  
Winter Temperatures ◽  
The U.S

Abstract The eastern United States experienced an unusually cold winter season during the 2002/03 El Niño event. The U.S. seasonal forecasts did not suggest an enhanced likelihood for below-normal temperatures over the eastern United States in that season. A postmortem analysis examining the observed temperatures and the associated forecast is motivated by two fundamental questions: what are these temperature anomalies attributable to, and to what extent were these temperature anomalies predictable? The results suggest that the extreme seasonal temperatures experienced in the eastern United States during December–February (DJF) 2002/03 can be attributed to a combination of several constructively interfering factors that include El Niño conditions in the tropical Pacific, a persistent positive Pacific–North American (PNA) mode, a persistent negative North Atlantic Oscillation (NAO) mode, and persistent snow cover over the northeastern United States. According to the simulations and predictions from several dynamical atmospheric models, which were not rigorously included in the U.S. forecast, much of the observed temperature pattern was potentially predictable.

scholarly journals Extended ENSO Predictions Using a Fully Coupled Ocean–Atmosphere Model

2008 ◽  
Vol 21 (1) ◽  
pp. 84-93 ◽  
Author(s):  
Jing-Jia Luo ◽  
Sebastien Masson ◽  
Swadhin K. Behera ◽  
Toshio Yamagata
Keyword(s):  
El Niño ◽  
General Circulation ◽  
El Nino ◽  
Southern Oscillation ◽  
Global Ocean ◽  
Enso Events ◽  
The Past ◽  
Ocean Atmosphere ◽  
First Time ◽  
Fully Coupled

Abstract Using a fully coupled global ocean–atmosphere general circulation model assimilating only sea surface temperature, the authors found for the first time that several El Niño–Southern Oscillation (ENSO) events over the past two decades can be predicted at lead times of up to 2 yr. The El Niño condition in the 1997/98 winter can be predicted to some extent up to about a 1½-yr lead but with a weak intensity and large phase delay in the prediction of the onset of this exceptionally strong event. This is attributed to the influence of active and intensive stochastic westerly wind bursts during late 1996 to mid-1997, which are generally unpredictable at seasonal time scales. The cold signals in the 1984/85 and 1999/2000 winters during the peak phases of the past two long-lasting La Niña events are predicted well up to a 2-yr lead. Amazingly, the mild El Niño–like event of 2002/03 is also predicted well up to a 2-yr lead, suggesting a link between the prolonged El Niño and the tropical Pacific decadal variability. Seasonal climate anomalies over vast parts of the globe during specific ENSO years are also realistically predicted up to a 2-yr lead for the first time.

The North Pacific Pacemaker Effect on Historical ENSO and Its Mechanisms

2019 ◽  
Vol 32 (22) ◽  
pp. 7643-7661 ◽  
Author(s):  
Dillon J. Amaya ◽  
Yu Kosaka ◽  
Wenyu Zhou ◽  
Yu Zhang ◽  
Shang-Ping Xie ◽  
...  
Keyword(s):  
El Niño ◽  
North Pacific ◽  
El Nino ◽  
Southern Oscillation ◽  
Deep Convection ◽  
Boreal Summer ◽  
Enso Events ◽  
The North ◽  
The North Pacific

Abstract Studies have indicated that North Pacific sea surface temperature (SST) variability can significantly modulate El Niño–Southern Oscillation (ENSO), but there has been little effort to put extratropical–tropical interactions into the context of historical events. To quantify the role of the North Pacific in pacing the timing and magnitude of observed ENSO, we use a fully coupled climate model to produce an ensemble of North Pacific Ocean–Global Atmosphere (nPOGA) SST pacemaker simulations. In nPOGA, SST anomalies are restored back to observations in the North Pacific (&gt;15°N) but are free to evolve throughout the rest of the globe. We find that the North Pacific SST has significantly influenced observed ENSO variability, accounting for approximately 15% of the total variance in boreal fall and winter. The connection between the North and tropical Pacific arises from two physical pathways: 1) a wind–evaporation–SST (WES) propagating mechanism, and 2) a Gill-like atmospheric response associated with anomalous deep convection in boreal summer and fall, which we refer to as the summer deep convection (SDC) response. The SDC response accounts for 25% of the observed zonal wind variability around the equatorial date line. On an event-by-event basis, nPOGA most closely reproduces the 2014/15 and the 2015/16 El Niños. In particular, we show that the 2015 Pacific meridional mode event increased wind forcing along the equator by 20%, potentially contributing to the extreme nature of the 2015/16 El Niño. Our results illustrate the significant role of extratropical noise in pacing the initiation and magnitude of ENSO events and may improve the predictability of ENSO on seasonal time scales.

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